I am an associate professor affiliated with the Department of Earth and Space Sciences and the Department of Physics and Astronomy at UCLA. With students and postdocs in a lively research group, I study the formation and evolution of planets with the tools of Astronomy, Geophysics, and Dynamics. You can use the navigation links on the banner above to learn more about my teaching and research interests.

Here is my CV and contact information.

If you are wondering what academics do in addition to teaching, I send sporadic updates to a twitter account, along with some news about science and education.

News:

Large scale study of the effect of sunlight on asteroid orbits (2012 Apr 26).

We have identified and quantified changes in the orbits of 54 Near-Earth Asteroids due to the effect of sunlight. Understanding this effect is important as it represents the biggest source of uncertainty in trajectory predictions of potentially hazardous asteroids. Our manuscript is available here.

Predictions of additional planets in multi-planet systems (2012 Mar 13).

At least 8 planetary systems discovered by the Kepler mission, and possibly many more, are likely to harbor additional, yet-to-be discovered planets. Our paper, Predicting Planets in Kepler Multi-Planet Systems, will appear in the Astrophysical Journal.

Observations of the Galilean satellites (2011 Oct 22).

We are measuring the spin states of Europa and Ganymede with the goals of quantifying tilts in spin axes and oscillations in spin rates. These measurements can inform us about the interior structures, geological processes, and astrobiological potential of these icy moons .

Five years at eight planets (2011 Aug 24).

Five years ago the Astronomical community defined what it takes to be a planet. Most people have easily adjusted.

"Where is MESSENGER?" smart phone application released (2011 Apr 7).

To help my colleagues and I keep track of MESSENGER's position in its orbit around Mercury, I wrote a small application for smart phones.

MESSENGER in orbit! (2011 Mar 17).

Instruments aboard MESSENGER are returning a wealth of new data about the enigmatic planet Mercury. My role on the Science Team is to combine spacecraft and ground-based data (gravity, topography, dynamics) to characterize the interior of the planet.

A planetary taxonomy proposal (2009 Jun 9).

A special session at the 214th meeting of the American Astronomical Society in Pasadena, CA was devoted to "Planet Classification in the 21st Century". My presentation can be downloaded here.

First detection of the YORP effect (2007 Mar 07).

Radar and optical observations of asteroid (54509) YORP provided the first direct observational evidence that sunlight modifies the spin of asteroids.

Observations of asteroid 2000 BD19 at Arecibo Observatory (2006 Feb 25).

Successful observations at Arecibo Observatory provided precise range measurements to the asteroid 2000 BD19, which comes very close to the Sun (the closest approach distance is only 20 times the radius of the Sun). The asteroid's orbit is perturbed by general relativity and the non-spherical shape of the Sun.

Contact: